Compounds suitable for moisturizing a nasal cavity or a portion of a nasal cavity are desirable for several reasons. For example, application of a moisturizer to the nasal cavity may facilitate and/or promote healthy function of the cavity, which in turn may reduce the duration of symptoms associated with, for example, a common cold or the flu, and which may reduce the likelihood of an infection in the nasal region.
In general, the nasal cavity performs several functions. The lower portion of the cavity includes the nasal epithelium, which is an essential part of the respiratory tract. The nasal epithelium is very vascular, which allows the epithelium to warm inspired air. The epithelium is also relatively moist, which allows it to moisten and cleanse inspired air. The cavity also includes a mucous membrane which lines the nasal cavity and traps fine particles such as dust, pollen and smoke.
Nasal epithelial cells play an important role in warding of both bacteria and viruses. The cells act as a chemical, mechanical and microbiological barrier to infection. Typically, small glands within the nose secrete mucus, onto the nasal epithelial cells to moisten a portion of the nasal membrane. The cilia, hair like structures implanted in the epithelium and the immune system's first line of defense, are the cells responsible for trapping dust and bacteria. When the nasal membrane becomes dry, the cilia's movement slows and bacteria are better able to enter the respiratory system. To effectively function, the epithelial cells must generally be healthy and moist.
Substances within air often act to irritate and dry out the nasal cavity. Sinusitis and allergens are two common conditions that affect the proper functioning of the nasal membrane. Sinusitis is an infection of any of the four groups of sinuses that prevents the proper drainage of mucous in the sinus passages. Sinusitis may stem from a cold or flu, allergies, pollution, injuries or various other conditions, which often result in a dry nasal passage.
Inhaled allergens, including dust, pollen, molds, animal dander, and grass may react with the mucous membrane. This reaction may result in a drying or irritation of the nasal cavity. These factors along with dry climates, changing seasons, and pollution can all lead to nasal cavity dryness which may cause cracking and bleeding of the nose as well as various other acute or chronic conditions. Accordingly, methods and compositions for moisturizing a nasal membrane are desired.
Presently, common treatment for nasal membrane dryness is either use of low-viscosity composition nasal sprays or use of a humidifier. Low-viscosity, over the counter nasal sprays generally remain in the nasal cavity only for a short period of time and therefore may be relatively ineffective at treating dry nasal cavities. A humidifier generally requires that the subject utilizing the humidifier remain proximate to the humidified air for a period of time and such use may therefore be problematic or undesirable in some instances. Accordingly, improved compositions, systems and methods for moisturizing the nasal membrane are desired.